Field of the Invention
The present invention relates to a monitoring system for monitoring a state of a fluid in an indoor space.
The present invention further relates to a method for monitoring a state of a fluid in an indoor space.
The present invention further relates to a climate control system including the monitoring system.
The present invention further relates to a climate control method including the monitoring method.
Related Art
In particular in indoor climate control systems it is desired to determine the actual state of the indoor climate, i.e. the state of a fluid, in an indoor space, such as a greenhouse. The state of the fluid may comprise a temperature field of the fluid, a flow field of the fluid, and a humidity field. In particular measurement of the flow field is complicated.
According to a known approaches a smoke source is placed in the indoor space and it is optically determined how the smoke moves through the indoor space.
According to another approach air currents are monitored by particle image velocimetry (PIV). This method is similar to the smoke tests, but allows for a quantitative measurement by the use of tracer particles and cameras.
Also methods are known to measure air flow at particular positions. However, as air velocities in an indoor space typically are low, only two principles are appropriate to achieve this.
One of these is hot-wire anemometry. According to this method a wire or bead is held at a constant temperature. The amount of energy that is required to keep the wire/bead on temperature provides information about the air flow. The magnitude of the air flow at a point can thus be determined. In order to also provide information about the direction a combination of wires may be used. Alternatively structures may be applied that are selectively sensitive for air currents in a particular direction.
Another one is ultrasonic anemometry. Therein ultrasonic transducers couples are used which measure a delay between the transmitter and receiver. The delay is indicative for the temperature and air flow in that direction. Three mutually perpendicularly arranged couples allow for an accurate three-dimensional flow measurement and the average temperature between the transducers. A similar method is based on Laser Doppler anemometry.
From the data so obtained the entire flow field can be reconstructed in an additional step, such as interpolation, acoustic tomography and filtering methods that are adapted for use in non-linear systems, such as ensemble Kalman filters, unscented Kalman filters and particle filters.
The known methods have the disadvantage that the sensors that are used to gather the raw data are expensive, and therewith inattractive for use, in particular in large indoor spaces.
It is noted that US2011/0060571 discloses a thermal-fluid-simulation analyzing apparatus including
(a) an execution unit that generates an analysis model using analysis conditions to conduct a first thermal fluid simulation analysis based on the generated analysis model,
(b) an analysis-condition collecting unit that collects analysis conditions when a predetermined period passes after the first thermal fluid simulation analysis,
(c) a condition extracting unit that extracts a boundary condition from the analysis conditions collected by the analysis-condition collecting unit, and
(d) a re-execution unit that selects a region corresponding to the boundary condition extracted by the condition extracting unit from regions of the analysis model generated by the execution unit, updates the selected region with the boundary condition, and conducts a second thermal fluid simulation analysis for the updated analysis model.
The known thermal-fluid-simulation analyzing apparatus is used for climate control in data centers that have a specific hot/cold aisle setup, and cooling through a plenum with perforated tiles. This is an idealized situation in that the general shape of the flow pattern is well known. Generally, in indoor climate control, e.g. in greenhouses, this is not the case and more complicated simulation models are necessary. This also implies that the results obtained indirectly from the measurements are more susceptible for noise.